Almost everywhere in the world, in summer you feel the day longer, the dawn comes earlier, you feel the sunlight from 3 am khổng lồ 9 pm everyday. However, the habit of most people is the same, sleeping at 12 am & getting up at 6 am.

Bạn đang xem: Daylight saving time là gì

Our earth revolves around the sun và rotates on its axis. In summer, in some parts of the earth such as some parts of the United States và Canadomain authority, you can clearly feel the dawn starting at 2 am. This time people are still sleeping & they only wake up in 4 hours.

The story began in 1907. An English builder named William Willet, during an early morning horsebachồng ride, noticed that all the houses were tightly closed and everyone was asleep although the sun had risen, và he felt that daylight was being wasted.
His idea at the time was how about people went khổng lồ bed earlier at 11 pm the day before and woke up at 5 am the next day. Or alternatively, in spring & summer everyone should turn their clocks 1 hour faster, & he called it "Daylight Saving Time - DST". 12 am and 6 am in DSTcorrespond to 11pm và 5 am in standard time. By the trick of the clocks, people keep their habits while saving daylight time.
Willet spent a small fortune lobbying businessmen, members of Congress, and the United States Congress lớn get his ideas realized. But his proposal was met with ridicule for the most part. One community opposes it for moral reasons, calling it the crime of "lying" about real-time.
Attitudes changed after World War I broke out. The government & citizenry recognized the need khổng lồ conserve sầu coal used for heating homes. The Germans were the first lớn officially adopt the light-extending system in 1915, as a fuel-saving measure during World War I. This led to the introduction in 1916 of British Summer Time: From May 21 to October 1, clocks in Britain were put an hourahead.
Despite major opposition from the public, the matter was eventually brought lớn parliament. In 1918, DST was tested in the United States. Two o"clock in the morning of March 31, 1918, all of the clocks in the United States were advanced an hour. Canadomain authority also applied a similar policy at the end of that year.

However, in the United States the Daylight Saving Time experiment lasted only until 19đôi mươi, when the law was repealed due khổng lồ opposition from dairy farmers (cows don’t pay attention to clocks). No fewer than 28 bills to lớn repeal Daylight Saving Time had been introduced khổng lồ Congress, và the law was removed from the books.

Xem thêm: Nghĩa Của Từ Ladle Là Gì - Nghĩa Của Từ Ladle, Từ Ladle Là Gì

The topic of DST was forgotten until America was dragged into lớn World War II after the attaông chồng on Pearl Harbor. DST is now required khổng lồ save energy.
Inconsistent adherence to lớn time zones amuốn the statescreated considerable confusion with interstate bus & train service. To remedy the situation, Congress passed the Unisize Time Act in 1966, establishing consistent use of Daylight Saving Time within the United States: Clocks were khổng lồ be phối ahead one hour on the last Sunday in April và one hour baông chồng on the last Sunday inOctober.
In 1986, theU.S.Congress approved a bill khổng lồ increase the period of Daylight Saving Time, moving the start to lớn the first Sunday in April. The goal was lớn conserve sầu oil used for generating electricity—an estimated 300,000 barrels annually.(In 2005, theentire state of Indiana became the 48th state to observe Daylight SavingTime.)
The rules for DST changed in 2007 for the first time in more than đôi mươi years. The new changes were enacted by the Energy Policy Act of 2005, which extended the length of DST in the interest of reducing energy consumption. The rules increased the duration of DST by about one month. DST is now in effect for 238 days, or about 65% of the year, although US Congress retained the right lớn revert khổng lồ the prior law should the change prove sầu unpopular or if energy savings are not significant.
Currently in the US, DST starts on the second Sunday of March và ends on the first Sunday of November. It is applicable to most US states.
Hawaii và Arizona are the only two states in the U.S. that vì not observe daylight savings time. However, several overseas territories bởi vì not observe daylight savings time. Those territories includeAmerican Samoa,Guam,Northern Mariamãng cầu Islands,Puerto lớn Rico, và the U.S. Virgin Islands.

United States
European Union
YearDST Begins at 2a.m.DST Ends at 2a.m.Summertime period begins at 1a.m.UTSummertime period ends at 1a.m.UT
2017March 12November 5March 26October 29
2018March 11November 4March 25October 28
2019March 10November 3March 31October 27
2020March 8November 1March 29October 25
2021March 14November 7March 28October 31
2022March 13November 6March 27October 30
2023March 12November 5March 26October 29

These are online courses outside the website that we introduced, which may include không tính phí or discounted courses.

Xem thêm: Club Là Gì, Nghĩa Của Từ Club, Bar Pub Phân Biệt Bar Pub Club

The trang web was created in March năm trước by a group of programmers & authors from Vietphái mạnh.Currently, the project supports 5 languages, including English, French, German, Russian và Vietnamese.